中国物理B ›› 2004, Vol. 13 ›› Issue (7): 1149-1155.doi: 10.1088/1009-1963/13/7/033

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Study of BaxSr1-xTiO3 thin films using transverse-field Ising model

蒋青1, 陶永梅2   

  1. (1)Department of Physics, Suzhou University, Suzhou 215006, China; (2)Department of Physics, Suzhou University, Suzhou 215006, China; Department of Physics, Changshu Institute of Technology, Changshu 215500, China
  • 收稿日期:2003-11-13 修回日期:2003-12-29 出版日期:2004-07-05 发布日期:2005-07-05

Study of BaxSr1-xTiO3 thin films using transverse-field Ising model

Tao Yong-Mei (陶永梅)ab, Jiang Qing (蒋青)a   

  1. a Department of Physics, Suzhou University, Suzhou 215006, China; b Department of Physics, Changshu Institute of Technology, Changshu 215500, China
  • Received:2003-11-13 Revised:2003-12-29 Online:2004-07-05 Published:2005-07-05

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摘要： In this paper, the effects of doping on the thermodynamic properties of Ba_xSr_{1-x}TiO_3 (BST) thin film are investigated, based on the transverse-field Ising model (TIM) within the framework of mean field theory. We apply the double-peak distribution model of related parameters to mimic doping. The lattice expansion arising from doping with large Ba^{2+} was also taken into account. We concentrate on the doping concentration dependence of peak temperature (T_m), spontaneous polarization and dielectric susceptibility. It is found that the doping concentration has great influence on the dielectric properties and phase transition properties of BST thin films. We also discuss the quantum effect arising from doping.

关键词: BST thin films, critical behaviour, TIM

Abstract: In this paper, the effects of doping on the thermodynamic properties of Ba$_x$Sr$_{1-x}$TiO$_3$ (BST) thin film are investigated, based on the transverse-field Ising model (TIM) within the framework of mean field theory. We apply the double-peak distribution model of related parameters to mimic doping. The lattice expansion arising from doping with large Ba$^{2+}$ was also taken into account. We concentrate on the doping concentration dependence of peak temperature ($T_{\rm m}$), spontaneous polarization and dielectric susceptibility. It is found that the doping concentration has great influence on the dielectric properties and phase transition properties of BST thin films. We also discuss the quantum effect arising from doping.

Key words: BST thin films, critical behaviour, TIM

中图分类号: 

  • 77.55.+f
68.55.Ln (Defects and impurities: doping, implantation, distribution, concentration, etc.) 77.22.Ej (Polarization and depolarization)